Method of making a decorative surface covering product



Q'g iQ E KR June 2, 1959 w.-E; BENEDKCT 2,383,975

maoa or MAKING A DECORATIVE SURFACE covaamc paonucr Filed July 22, 1958r i g? a zzvmvrox.

HHWIIMIQWG ilnitcd States Patent nice.

Patented done 2, 1959 2,888,975 I. 91 MAKING A DECQRATH E SURFACECQVERING PRGDUCT Walter E. Benedict, Newtown, Pa, assignor toCongoleum-Naim Inc, Kearney, NJ, at corporation of NewYork ApplicationJuly 22, 1953, Serial N0. 750,240 14 (Zhims. (Ci. 154- 125) Thisapplication is a continuation-in-part of my pendlog application SerialNo. 508,449, filed May 16, 1955 and now abandoned.

Composition material has been used very extensively for the decorativeand wear-resistant layer comprised in flexible, smooth surfacecoverings. Composition sheets usually are'made adherent to a backingsheet such as bituminized felt or a fabric, but composition. sheetmaterial can be used by itself, e.g., in the form of tiles. Cornpositionsheets for such purposes may be manufactured by sheeting out asubstantially homogeneous mixture of to produce a sh :et having a .1 androde: material an... substantially uniform wlcr. Composition sheetshaving only a single color are must generally usocii in oflices, stores,and other public buildings. However, for such purposes, as well as inthe field of multiple or single dwellings, more decorative effects arefrequently desired wherein more than one color is utilized.

In the production of decorative effects using more than one color,coverings of the linoleum type have been made by depositing or inlayingpieces of different color and complementary shape onto a common backingsheet. 1 he decorative effects produced in this way are of the geometrictype, e.g., a checkerboard arrangement of square pieces of contrastingcolor or polygonal pieces of one or more color that are inlaid incorresponding cutouts from a continuous sheet of contrasting color-- soas to form a predetermined pattern- The production. of coverings of theinlaid linoleum type involves the employment of a backing sheet such asbituminized felt on which pieces may he inlaid and the operation is onerequiring the use of large and expensive equipment for cutting out thepieces from a plurality of calendered sheets of linoleum composition orthe like, carrying the backing sheet of bituminized felt on a movingsupport, depositing the desired cutout portions or pieces of thecdendered sheets on the backing sheet at ditiercnt of travel of thebacking sheet, rejecting and taking away the unwanted portions or piecesof the calcudered sheets, and finally merging or fusing together theedges of the pieces that have been deposited on the backing sheet ininterfitting inlaid relation. Because of the nature of the apparatus andmethod employed in making inlaid linoleum, the decorative effectsproduced are limited to designs of the geometric repeat type. Moreover,because any changeover from one design to another requires verysubstantial and costly changes in equipment, the number of designs thatmay, as a practical matter, be placed on the market by a particularconcernis very l mited. It is also a drawback to the inlaying methodthat a serious salvage probram is presented by reason of the unwantedportions of the calendered sheet material that do not enter nto theparticular design being produced- For example. it not infrequently isthe case that less than i6% of a calendered sheet having a par'icula:coloration is required for entering into the intended design, theremaining of the calender-ed sheet being essentially scrap. In manyinstances, the salvage of this scrap is inconvenient to arrange andproblems of storage are encountered not only as regards storage spaceand handling expense but also as regards the limits of time that thecomposition may be stored without becoming unworkable. Heretofore, ithas been impossible to adapt the above-described process for preparingcoverings of the vinyl type.

More intricate decorative efiects haraheen produced on coveringmaterials by applying pain, lace-per, or the like to a suitable backingsheet such as bituminized felt by means of block printing or otheranalogous operations. Since coverings of this type have a wear layerwhose thickness is provided merely b the paint or lacquer that has beenapplied as a coating, their wearing life is much less than that ofinlaid linoleum wherein the wear-resistant layer is provided bycalendering linoleum composition :0 whatever thickness may be desired,such thickness being many times the thickness of paint or lacquerapplied as a coating.

As distinguished from applying difierently colored pieces of calenderedlincieunz composition to a backing sheet or applying paints or lacquersof dilicrent color to a base sheet, calendered sheets of compositionmaterial such as linoleum composition have been produced which are ofvariegated appearance by mixing together pieces of the compositionmaterial having different color and, while the mixed 'ecs are of aplanic md moldable core sistency, subiecting them to one or morecalendering operations under conditions which are suitably controlledfor producing the appearance desired. For example, linoleum compositionmay be formed prior to calendering into pieces about to 1 inch in lengthand having a transverse dimension of about M. inch. Pieces of differentcolor that have been so formed are mixed together until the relativeproportion of the pieces of ditierent color is about the same in allportions of the mixture. The mixture is then fed into a calender andduring passage through the calendar the pieces largely retain theirindividual colors but are subjected to very substantial distortional comming ing. This distortional commingling is evidenced in the product ofthe first calendaring by the fact that the pieces have become stretchedout into long streaks to provide a striated efiect that is commonlyreferred to as jaspc.

In addition to the iaspe efleet, a simulated marble efiect may beproduced by further distortionrl. commiegling of the pieces ct dilierentcolor. This usually is accomplished by cutting a previously formed iaspesheet into lengths, turning the lengths 9'), lappirg the turned lengthsand carendering the lapped lengths. The lapped jaspe sheets me thencross calendered, that is, calendcred in a direction 90 to the directionof the jaspe streaks, and by so doing the iaspe streaks are spreadsidewardly with resultant production of an appearance resembling marble.

Variegated color effects likewise have been produced, particularly inconnection with relatively heavy comp. sition sheets, e.g., suitable fortiles, l'y initially formin-x by passage between rolls a sheet havingsubstantially uniform color throughout and than prior to furtherfern-ration of the finished sheet by pas age betw en rolls adding piecesof contrasting color which may be of the charac er aforesaid and ofessentially the same plastic consistsicy as that of the sheet to whichthey are added. so that upon being subjected to calendaring with theirfiall? formed relatively to the surface of the sheet being calendered,

the dragging out of the colors in the direction of the calendaring canbe accentuated, and particularly if the roll in contact with one of thesurfaces is operated so as to be at a temperature which increases thesuperficial plasticity oi the composition in contact with the roll. acertain amount of surface smearing of the colors may be produced.However, in any case the variegated appearance that resulting fromrandom and very extensive distortional commingling of portions of thefinished sheet of composition material. Sheets having this type ofdecorative appearance are extensively used by causing them to adhere toabaclting sheet such as bituminized felt to produce linoleum of thewell-known jaspe or marbleized types as well as in the production ofasphalt tile. if desired in the case of linoleum, calendered sheetmaterial of this type may be fed into an inlaying machine and pieces maybe cut therefrom for providing certain of the pattern elements of inlaidlinoleum. The heavier grades of such sheets likewise may be cut intotiles.

Polyvinyl composition has heretofore been employed for providing thewear-resistive layer or sheet comprised iu fiexibe smooth surfacecoverings. Thus calendered polyvinyl composition sheets have been bondedto backing sheets such as bituminized felt. The decorative features ofpolyvinyl composition coverings have been somewhat more limited ascompared with coverings comprising linoleum composition due primarily tothe fact that the workability of polyvinyl composition depends upon itsthermoplastic properties whereas linoleum composition can be worked atroom temperature while the drying oil component of the binder is in anonly partially oxidized and polymerized condition. Thus in the case ofpolyvinyl compositions relatively high temperaturcs are employed of theorder of 250 F. to 350 F. during the operations of mixing and sheetformation. For this reason vinyl composition coverings have either beenproduced in plain colors or with variegated appear ance such as jaspe ormarbleized appearance when a con tinuous process has been employed. Thishas been a serious limitation on the decorative and ornamental effectsthat are obtainable using this type of covering. Eltorts directed to aoid this limitation usually involve a process wherein differentlycolored areas of granulated vinyl composition are physically placed on abacking or in a mold in a predetermined arrangement. Most frequently,this process is limited to providing thicker products, on the order ofMs inch, because of its slow operation and great expense. Polyvinylsheets are frequently cut into tiles.

It is an object of this invention to provide a flexible smooth surfacecovering comprising a decorative sheet of composition materialpresenting surface areas of contrasting color, the sheet havingextremely long-wearing charazteristics cmnparabl: to coverings of theinlaid linoleum type while at the same t me being capable of manufactureat much less cost both as regards processing 4 going -improvements in acomposite sheet composed of polyvinyl composition.

Other objects of this invention relate to the provision of an improvedmethod for making a composite sheet of vinyl composition having areas ofcontrasting color whereby sharply defined predetermined boundar esbetween the areas of difierent color are produced. Other objects of thisinvention are to provide a method of producing a composite sheet havingthe characteristics aforesaid that is economical and operable at a highproduction rate.

It is a feature of this invention that a decorative and wear-resistantsheet of polyvinyl composition is provided which is composite in that itcomprises a matrix sheet and numerous pieces of contrasting color whichare embedded within recesses in one of the surfaces of the matrix sheetin substantially spaced relation with respect to each other with theexposed surfaces of the pieces substantially flush with the surface ofthe matrix sheet. The embedded pieces may be of substantially uniformthickness substantially throughout and are fused to the matrix sheet attheir interfaces therewith.

According to this invention, flat pieces are preformed from polyvinylcomposition which is similar to that of the matrix sheet except for thecontrasting color. The flat pieces may be produced in any suitable wayas by cutting them from a calendered sheet or by transversely slicing anextruded body whose cross section has the desired shape. Preferably, theflat pieces are somewhat thinner than the matrix sheet and are caused tobe pressed into the matrix sheet while the matrix sheet is at atemperature at which it is soft and readily deformable. The pressing isaccomplished with virtrally no distortional committgling of the pieceswith the matrix sheet and thereby they retain essentially their originalpredetermined shape and thickness. As a result, effects may be producedwhich in certain respects are similar to those obtained in the case ofinlaid linoleum in that the original contours of the pieces remainessentially the same and likewise are sharply defined and in that theoriginal surface pattern remains essentially the same during wearingaway of exposed surface over very long periods of wear. On the otherhand, ellects may be produced which ornamentally are distinctlydifferent from those that are ordinarily produced in making inlaidlinoleum in that arrangements and shapes can be obtained which arebeyond the capacty of machines for making inlaid linoleum. Thus pieceswhich have curved or other irregular outlines may be utilized asconveniently as the more regular and simpler pieces which are our andplaced in position in the manufacture of inlaid linoleum. Moreover. thepieces can be disposed in regularly recurring pattern repeat units or inscattered or random relation. In any such case both the manufacturingoperation and the machinery for carrying it out are much less costly ascompared with the manut'acture of inlaid linoleum.

In the practice of this invention, the pressing in of the preformed flatpieces into the matrix sheet without substantial distortions comminglingis effected when the exposed surfaces of the pieces are at asubstantially lower temperature than the temperature to which the matrixsheet is heated. For example, such temperature differential may bepartially or entirely obtained by causing the pieces to be in contactwith a surface that is maintained at a relatively low temperature. inaddition, an initial temperature diiierential between the pieces and thematrix sheet may be employed. By use of a, pressing part maintained at alower temperature, ditficulties due to sticking ikewise are overcome.During the pressing step, the matrix sheet preferably is maintained incontact with a surface presented by a body of substantial thicknesscomposed of a yicldable resilient material such asmbber or a syntheticrubber although the conventional steel or chrome plated rolls can beused. The pressing step between surfaces is of such character that itcan conveniently be carried out as a continuous operation using opposedrolls into which the matrix sheet having the pieces deposited thereon isfed after having been heated until the vinyl composition of which it iscomposed is rendered soft and deformable.

After the pressing step, the resulting composite sheet need only becooled before use because during the pressing of the pieces into thematrix sheet the pieces become fused with the matrix sheet at heirinterfaces therewith. If the surface of the matrix sheet opposite tothat into which the pieces are pressed becomes bulged to some extent inthe locations where the pieces are pressed in, the composite sheet canbe passed in operative relation to a mechanism for planing off thebulges so that the composite sheet will be substantially of uniformthickness throughout.

Any of the polyvinyl compositions suitable for lamination with a backingsheet or for use in the form of tiles may be employed in the practice ofthis invention.

Suitable polyvinyl compositions are disclosed in Patent No. 2,558,378.While, as s ated in this patent, various polyvinyl compounds may beemployed, that which is must generally employed is vinyl chloride-vinylacetate copolyrner containing from about 80% to about 98% by weight ofvinyl chloride. The resinous polyvinyl compound is plasticized by any ofa number of plasticizers such as tricresyl phosphate, dioctyl phthalateand chlorinated parafiin. The plasticized polyvinyl compound binder ismixed with suitable fillers and p gments which may constitute fiom about20% to about 76% by weight of the composition, e.g., calcium carbonate,clay, silica flour, etc., as well as pigments which are selecteddepending on the color desired. Generally it is preferable to employ asubstantial amount of a fibrous filler such as short asbestos fiber.Typical formulation comprises from about 20% to about 50% of polyvinylresin, about 10% to about 30% of plasticizer and about 20% to about 70%of filler including pigments. Such and similar composition material isreferred to herein and in the claims as polyvinyl composition, and maybe utilized in the practice of this invention.

In the practice of this invention, the thermoplastic properties ofpolyvinyl composition which in certain respects present diiiiculties inthe successful manufacture of flexible smooth surface coverings havebeen utilized to advantage and; in fact, this invention involves a novelutilization of thcpeculiar properties of polyvinyl compositions. Thuswhile polyvinyl composition generally is mired and sheetedattemperatures in the range from about 259 F. to about 350 F., a sheetwhich has been formed as by calendering may be heated to still highertemperatures ranging from about 350 F. to about 390 F. and while thecomposition at such temperatures becomes soft and readily deformable, itcan be handled and even passed between roiis while retaining its desiredbe pressed into a matrix sheet hat has thus been highly heated withlittle or no deformation of the preformed pieces. This is especially thecase if the temperature of the pieces is held down at least at andadjacent the exposed surfaces thereof. When the matrix sheet is at suchelevated temperatures, and even though the pieces are not substantiallydeformed, the pieces become fused to the matrix sheet so that there isno discontinuity of.

It is an advantage and unique attribute of this invention that thepressed-in flat pieces may be of any shape and may be of any sizeconsistent with the capacity of the pieces to be pressed into the matrixsheet while the matrix sheet is heated to a emperature at which it isdeformable and fiowable when the pieces are pressed into the matrixsheet. In order to permit the pieces to be pressed into the matrix sheetin an operation which may be readily carried out comercially, itisusually desirable that the pieces not have an area greater than about 2%square inches. It has been found that pieces of this size and smallerare actually imbedded in the matrix sheet and result in only a minimumamount of lateral or longitudinal displacement of material of the matrixsheet. On the other hand, if the total surface area of the piecesexceeds about 2% square inches, the pieces are laminated to the matrixsheet and considerable displacement of material occurs. This seriouslydisturbs any pattern which may be present on the matrix sheet and tendsto create areas of unevenness on the final composite sheet. When pieceshaving a surface area less than about 2% square inches are imbedded inaccordance with the invention, there or no discernible lateral orlongitudinal displacement of material of the matrix sheet. Apparentlythe composition is compacted or pressed to the hack of the sheet. E enwhen using pieces measuring over about 1 square inch, care should beexercised to avoid close placement of the pieces to each other as thesmall amount of lateral and/or longitudinal displacement which doesoccur will result in slight surface unevenness of the final sheet. It isfor this reason that the use of fiat pieces having a surface area of 1square inch or less is most preferred in the practice of the invention.In addition, pieces which have a greatest surface dimension whichgreatly exceeds any other dimension, such as length compared to width,are somewhat difficult to handle in processing particularly inconnection with placementand control of decoration other than of therandom type. The pieces may be made so as to have a relatively smallarea if desired. as for example if an effect of the type which iscommonly referred to as a salt and pepper effect is desired. However,the pieces should be such that when deposited on the matrix sheet theywill lie fiatwise thereon so that after the pieces have been pressedinto the matrix sheet, the surface of the pressed-in pieces will liesubstantially flush with the surface of the matrix sheet and in the sameplane so that the covering will present an over-all smooth surface. whenreference is made to the area or dimension of the pieces, the referenceis to the area or the linear dimensions of the exposed surface unlessotherwise clearly defined.

he thickness of the matrix sheet and the thickness of the pieces dependsupon the desired thickness or the composite sheet for use in thecommercial product for which the composite sheet is intended. Forexample, in the production of a laminated covering comprising adecoratlve and wear-resistant layer which is bonded to a backing sheetsuch as bituminbed felt, the decorative and wear-resistant layer whenmade according to this invention may typically be about 0.025 inch inthickness. Usually it is desirable that this layer not be below about0.029 inch in thickness. On the other hand, heavier grades of suchcoverings may be produced if desired. If

" thc composite sheet is to be used in the manufacture of tiles withouta backing composed of nonvinyl material. the sheet that is produced isusually about 0.080 inch or greater in thickness.

The pieces which are pressed into the matrix sheet preferably aresubstantially thinner than the matrix sheet. For example, the pieces maydesirably be about one-third the thickness of the matrix sheet. If thepieces are thinner, then the serviceahility of the covering is not asgood. If the pieces are flicker than about one-half the thickness of thematrix shoot, them greater difficnlty is encountered in pressing theminto the matrix sheet without the production of an undesirably largeamount of bulging at the opposite surface of the matrix sheet. How

ever, pieces have been successfully pressed into the matrix sheet whichare nearly the same thickness as the matrix sheet and which have beenover 75% or the thickness cf the matrix sheet. As is apparent it isusually necessary to reduce the gauge of the matrix sheet while pressingin the pieces to produce a smooth, glossy surface on the sheet. By wayof more specific example, when the composite sheet is to be about 0.025inch in thickness, the pieces may be about 0.015 inch in thickness andthe matrix sheet prior to pressing about 0.035 inch in thickness.

Further objects, features and advantages of this invention will beapparent from the following description of the accompanying drawingswhich are illustrative of the practice of this invention and wherein:

Pig. 1 is a plan view on a reduced scale of a flexible smooth surfacecovering which illustrates certain of the effects that may be producedaccording to certain embodiments of this invention;

Fig. 2 is a fragmentary cross section of a flexible smooth surfacecovering comprising a composite sheet embodying this invention, thesection being on an enlargcd scale for increased clarity in the showing;

Fig. 3 is a diagrammatic side elevation which is illustrative of onetype of apparatus which may be used in the practice of this invention;and

Fig. 4 is a diagrammatic side elevation of a continua: tion of theapparatus shown in Fig. Swhich may be optionally used in the practice ofthis invention.

Fig. 1 illustrates the fact that the sheet-form pressedin pieces may beof virtually any shape such as rectangles, diamonds, crescents,elongated strips which may be either straight or curved, etc. The shapesof the pieces which may be readily used according to this inventionprovide much greater flexibility as regards the shapes of decorativedesign elements than is in any way practical in the case of inlaidlinoleum, whose manufacture requires very complicated and expensivemachinery for cutt ng out pieces from certain calendered sheets andfitting in pieces from other calendered sheets as to make up a mosaic.As shown in Fig. 1, the pieces are disposed in substantially spacedrelation. By the term substantially spaced relation as used herein andin the claims, it is intended that the pieces are spaced so that asubstantial portion of the matrix sheet is exposed. Ordinarily the majorportion of the surface of the composite sheet is that of the matrixsheet. in Fig. l the exposed area of the matrix sheet is indicated bythe reference character 10 and the reference character 11 is applied tothe various pieces. The composite sheet as a whole is indicated by thereference character 9. The spaced relationship of the pieces is not,however, to be regarded as precluding the possibility of two or more ofthe pieces contacting each other as illustrated, for example, by thepieces 11a. Likewise, two or more pieces may overlap each other asillustrated by the pieces 1112. Such contact or overlapping of pieces islikely to occur when the pieces are distributed in the random fashionillustrated in the ieftlsand portion of Fig. 1. Very pleasing decorativeeffects can be produced such random distribution of the pieces. On theother example, be bituminized felt.v A layer of bonding material may heused and is indicated by the reference character 13 and may comprise oneor more layers adapted to provide the necessary bond and, when desired,a seal to prevent migration of the binder in the backing sheet 12 intothe composite sheet consisting of the matrix sheet ill and the pieces11. It is to be noted in connection with Fig. 2 that the exposedsurfaces of the pieces 11 are substantially flush with the surface ofthe matrix sheet 10. Moreover, the pieces 11 are substantially the samethickness substantially throughout. This results from the fact that thepieces 11 before being pressed into the matrix sheet it? are sheet-formin that they have the shape of a piece cut from a larger sheet orproduced by cutting a thin layer of uniform thickness from an extrudedbody.

When the pieces 11 are pressed into the matrix sheet 10, they remainsubstantially unchanged and the interface between the pieces and thematrix sheet is sharply defined. This sharp definition is evident at thesurface of the composite sheet and likewise is'apparent if the sheet iscut transversely so as to show a section such as that illustrated inFig. 2.

In Fig. 3 there is illustrated one type of apparatus which may be usedin the practice of this invention. Any suitable source of a sheet ofpolyvinyl composi ion may be employed. In Fig. 3 a calender is shown ofthe type which is adapted to produce a calendercd sheet from an unformedmass of vinyl composition. The unformed vinyl composition is indicatedat 14 and may be vinyl composition which is of substantially uniformcolor throughout as, for example, a composition that results from mixingthe ingredients of a polyvinyl composition in a Banbury mixer. Thematrix sheet 10 is produced mm the mass 14 by passage between the rolls15 and 16, between the rolls 16 and 17 and between the rolls 17 and is.If it is desired that the matrix sheet 10 have a iaspe appearance. thenthe mass 14, which is initially formed by passage between the roll 15and 16, may he a mixture of pieces of vinyl composition of differentcolor of the type hereinabove referred to. If a marbleized base sheet isdesired, then previously formed and lapped iaspe sheets may be crosscaiendercd as by passage through a 3-roll calender arranged in themanner indicated by the rolls 16, 17 and 18. Any other type of calenderor sheet-forming apparatus may be employed foriniiial formation of thematrix sheet. Because of the nature of the polyvinyl composition, thematrix sheet as initially formed is at an elevated temperature which maybe from about 250 F. to about 356 F. Since the step wherein the piecesare pressed into the matrix sheet is carried out when the matrix sheetis in a highly heated and softened condition, it is preferable toproceed with the incorporation of the pieces into the matrix sheetimmediately after the matrix sheet has been formed at elevatedtemperature. As illustrated in Fig. 3, the ma rix sheet 10 immediatelyafter having been formed has the pieces 31 deposited thereon from thefeeding devices 19. This is conveniently done while the sheet 10 isbeing carried on the continuous conveyor belt 20 such as a steel meshconveyor. The feeding devices 15 have been indicated schematically bothbecause such suitable feeding devices are well known and because theparticular feeding device employed may take a number of different formsdepending upon the decorative effect desired. For example. the devices19 may consist of a belt type feeder adapted to distribute the pieces inrandom fashion at a controlled rate in relation to the rate of movementof the matrix sheet 10. Alternatively, a feeding device of the siftingtype may be employed for effecting random distribution of the pieces. Ifa predetermined pattern is desired, then the feeding devices 19 may besuch as to deposit the pieces at predetermined locations on the matrixsheet as the matrix sheet 10 is moved in opere ative relation therewith.For example, a feeding device may be used of the known type in which avacuum is used for picking up pieces on the surface of a rotat ingcylinder, the pieces thereafter being released for deposit on the movingmatrix sheet at desired locations. While two feeding devices 19 havebeen shown, this has been done merely for the purpose of illustratingthat either a single feeding device or a plurality of feeding devicesmay be employed depending upon the nature of the pieces to be depositedon the matrix sheet and the decorative effect that is to be produced.

While the matrix sheet 10 is preferably heated to a. temperature of theorder of about 250 F. to about 350 F. when the pieces 11 are depositedthereon, the pieces 11 preferably are deposited while at ordinary roomtemperature After the pieces 11 have been deposited on the matrix sheet10, the matrix sheet with the pieces deposited thereon is passed throughthe heating "unit 21, which may be of any suitable type adapted to raisethe temperature oi the matrix sheet to the temperature desired for thepressing step. For example, if the matrix sheet already is heated toabout 250 F., the heating unit 21 can readily raise the temperature ofthe base sheet to the desired temperature in only about to seconds. Forthis purpose the heating unit may be about 10 feet in length for atravel rate in the neighborhood of 40 feet per minute. Any suitableheating elements may be used and conventional infra-red heating elements22 are very satisfactory. it is desirable to dispose the heatingelements 22 underneath the matrix sheet 10 as well as above the matrixsheet 10, for the matter of primary concern is that of raising thetemperature of the matrix sheet and it is preferable to do so whileminimizing the heating of the pieces deposited thereon. It is usuallydesirable in order to obtain the desired plasticity and .tlowability ofthe matrix sheet by heating it to a temperature of about 330 P. to 390F., namely, to the highest temperature that the matrix sheet willwithstand without excessive decomposition and without such extremesoftening of the polyvinyl composition as to render further handling ofthe matrix sheet impossible or impractical. The precise temperature towhich the matrix sheet is heated will depend somewhat upon thecomposition of the matrix sheet. Thus increase in the amount ofplasticizer enables the matrix sheet to be softened at a lowertemperature than specified above. If the polyvinyl resin which is usedhas a lower softening point, this also results in lowering thetemperature to which the matrix sheet may be heated. The proportion ofthe filler is also significant for increase in filler component tends toincrease the temperature to which the polyvinyl composition should beheated in order to obtain good results.

The foregoing factors which affect the temperature at which the matrixsheet becomes softened also aifect the temperature at which the piecesbecome softened. Since it is desirablein the practice of this inventionthat the pieces retain as much as possible their original form thisobjective may be realized to somewhat better advantage by causing thepieces to be composed of polyvinyl composition having a substantiallyhigher softening point than that of the matrix sheet, e.g., by theemployment of less plasticizer in the formulation of the pieces.

While the heating of the matrix sheet has been shown in Fig. 3 as beingeffected after the pieces have been deposited on the matrix sheet, thesequence may be varied. For example, the matrix sheet may be passedthrough a heating oven prior to the deposit of the pieces thereon. Byparially heating the matrix sheet before the pieces are deposited on thematrix sheet, the extent to which the pieces are heated in asubsequent'heating step may be minimized in relation to the finaltemperature to which the matrix sheet is heated prior to the pressingstep.

sired spacing between the rails 23 and 24 and for maintaining thedesired pressure to be applied. Such means are conventional and for thisreason have not been shown in Fig. 3. The roll 23 presents a smooth,rigid surface suitable for imparting the desired finish to the compositesheet. Thus the roll may have a chromium finish or it may be a polishedsteel roll. Rolls of this type impart a high polish. If a surface finishof some other type such as a matte finish is desired, then the surfaceof the roll 23 may be appropriate for the production of such a finish.

The roll 24, as indicated in Fig. 3, is provided with a surface layer 25of yieidable resilient material. For example, the layer 25 on thesurface of the roll 24 may be about 1 inch in thickness and since thisroll comes in repeated contact wth the highly heated matrix sheet, thematerial of which the surface layer 25 is composed desirably is onewhich will withstand use at relatively high temperatures. A syntheticrubber material such as chlorobutadiene polymer or butadiene-styrenecopolymer is suitable for the purpose. However, since the gradualdeterioration is minimized by maintaining the temperature of the layer25 somewhat under 300 F, the roll 24 preferably has associated with itmeans for circulating a cooling fluid therethrougb. Rolls provided withmeans for circulating a cooling fluid therethrough are conventional inthe art and for this reason such cooling means has not been shown in thedrawing in the interest of clarity and simplicity. A similar comment isalso applicable in the case of the roll 23 which is operated at aconsiderably lower temperature than the roll 24. It is to be tmderstood,however, that the cooling of the roll 24 is effected only in theinterest of avoiding excessively rapid de erioration of the resilientsurfacing layer 25 for it is preferable to run the roll 24 at as high atemperature as possible so as to keep the matrix sheet in a soft anddeformable condition. Atemperature range of about 150 F. to an)" F. hasbeen found particularly substantially below that of the matrix sheet 10and it has been found to be desirable to maintain the surfacetemperature of the roll 23 at a temnezamre difi'erential of at leastabout 50 F. and preferably at least 75' F. By maintaining suchtemperature at the surface of the roll 23- any tendency of the compositesheet to stick to the roll 7.3 is avoided and any tendency to smear inthe regions of the demarcation between the pieces and the matrix sheetis reduced to a minimum. Moreover, by maintaining the surface of thepieces which come in contact with the roll 23 at a relatively low ternperature, the amount of defamation of the pieces from their originallypreformed shape during the pressing step s minimized. The tempera-hireand amount of the coolrng fluid passed through the roll 25 is controlledso as to mahxtain the desired surface tempermure at the surface of theroll 23. If necessary, water or brine at a temperature substzmtialiybelow room temperature may be emp'foyed.

When the heat plasticized man-ix med with the pieces placed thereon ispassed between the rolls 23 and 24, the surface-forming roll 23 ispreferably arranged with reference to the feed of the matrix sheet sothat it comes in initial contact with the exposed surfaces of thepieces, the roll 23 not coming incontact with the matrix sheet until thepieces have been pressed into the matrix sheet until their exposedsurfaces are flush with the Surface of the matrix sheet; This isdesirable bothfrom the point of view of keeping the pieces cool so as toretain their preformed shape and from the point of view of avoiding thecooling of the matrix sheetmnil thepieces have been pressed therein. Theresiiientlayctzs enables tin matrix sheet andthepic-eestobetalrenintethr nipbetweenthe rolls 23 and 24withoutbuildiugnp thank whemn ti:

softened polyvinyl composition becomes bunched or worked and results inmore uniform pressure application.

Merely by way of illustration, the roll 23 may be from about 18 to 24inches in diameter and the roll 24 may be from about 12 to 18 inches indiameter. The length of the rolls may be varied depending upon the widthof the composite sheet to be produced. Both rolls are dven at a rateadapted to receive the heated matrix sheet from the calendering andheating steps. Any suitable means (not shown) may be employed fordriving the rolls 23 an 24 and synchronizing their rate of rotation withthe other apparatus parts. a

While the operation preferably is carried out so that the pieces 11 areat a substantially lower temperature than the temperature of the matrixsheet, when the matrix sheet is caused to pass between the rolls 23 and24, the pieces 11 wlere they come in contact with the man-it: sheet areraised to such temperature that fllSlOil occurs so that there is nophysical discontinuity in the finished composite sheet but only adiscontinuity as regards color between the matrix sheet and the pieces.The pressure exerted between the rolls 23 and 24 is preferably justsufiicient to result in embedding the pieces 11 until their exposedsurfaces are substantially flush with the surface of the matrix sheet. Apressure of from about 200 to about 400 pounds per linear inch isordinarily sufficient. 0minarily pressure is applied by urging the roll24 upwardly by some suitable means (not shown) such as a pneumatic orspring means.

After the composite sheet has passed the zone of initial pressureContact, it is preferably carried on the surface of the roll 24 for asubstantial distance so that it may be cooled to a temperature at whichit may more readily be separated from the surface of this roll. Forexample,

the composite sheet may be cooled while on the sur- 3 face of the roll23 to a temperature of about 159 F. to 175 l and thereafter thecomposite sheet may be passed over cooling drums 26 on which it may becooled to ordinary room temperature. It is preferable, however, to stripthe composite sheet ofi of the surface of the roll while it is still hotto produce a glossy and polished surface.

The use of the process typified by the use of rolls 23 and 24 is greatlyadvantageous in the practice of the invention. In one operation thesurfaces of the decorative pieces are cooled by the action of the metalroll contacting them prior to its contacting the matrix sheet; theoverall sheet is rendered smooth by the pressing of the decorativepieces in the matrix sheet wifoout any substantial lateral orlongitudinal displacement of material of the matrix sheet; thedecorative pieces are immediately fused into the matrix sheet due to theheat contained therein yet there is little, if any, distortion of thedecorative pieces or the decoration of the matrix sheet; the compositesheet is further cooled and set in its final form; the resilient bottomroll prevents a build up of material in the nip of the roll which woulddestroy the decoration of the matrix sheet; and, in addition, the bottomroll minimizes the removal of heat from the matrix sheet thus permittingthe colder top mil to operate as described.

if desired, the composite sheet after havingpassed between the rolls 23and 24 may be subjected to oneormore additional pressing steps carriedout similarly and prior to substantial cooling of the composite sheet.However, if one or more additional pressing steps are utilized, thecomposite sheet may be subjected to reheating prior to any one or moreof such repeated pressing steps.

v After the composite sheet 9 has become cooled by passage over thecooling rolls 26, the sheet is ready to be comprised in a commercialproduct. Thus the composite sheet may be bonded with a backing sheetsuch as full or a second vinyl sheet to provide a coming of the typegauge may be cut to form tile adapted for use without any backing.

Depending upon the operating conditions during the pressing step,including the temperature and composition of the matrix sheet and thearea and thickness of the sheet-form pressed-in pieces, the matrix sheetmay to some extent become bulged outwardly in back in those locations vwhere the pieces are pressed into the matrix sheet. When the finishedcomposite sheet is caused to be laminated with a. sitznninous backingsheet that has been heated to a temperature at which it is substantiallysoftened when the lamination is caused to occur utilizing substantialpressure, such bulges as may occur in the back of the matrix sheet maybecome absorbed by and counter sunk in the backing sheet so thatnotwithstanding the bulges the finished lam'nated covering of uniformgauge throughout. If, however, the l 'lges are regarded as excessive forsuch use or if it is desired that the composite sheet be of uniformgauge so that it may be used for the manufacture of tiles, for example,the bulges may be removed by planing them off as, for example, by amechanism such as that indicated diagrammatically in Fig. 4.

As shown in Fig. 4, the composite sheet 9 may be taken from the coolingdrums 26 so that the undersurface of the composite sheet will be passedin operative relation to an abrading means such as the roll 27 which hasan ahrading composition, as, for example, sandpaper, on the surfacethereof. In order that the sheet 9 may be held in proper relationship tothe surface of the abrading roll 27, the roll 28 may be employed as anordinary steel roll. By rotating the roll 27 so that its peripheralabrasivc-presenting surface is moved relatively to the undersurface ofthe composite sheet 9, any bulges are effectively planed 0E and removed,with the resultant production of a composite sheet that of uniform gaugethroughout. Any material 39 that thus planed oil may be collected bysuitable means such as that irdicarcd diagrammatically by the referencecharacter 29 and, if desired may be incorporated with the compositionmaterial that is used either in the initial production of the matrixsheet or in the production of some or all of the fiat pressed-in pieces.The following example is given for the purpose of i lushation:

Example A vinyl composition matrix sheet six feet wide and; 0.035" thickwas produced having the following composi-} tion: Parts by weightCopolymer of vinvl chloride and vinyl acetate 316 Dioctyl phthalate 126Asbestos fiber 140 Wood hour 30 Dry ground limestone 100 1 Silica flour215 Stearic acid 2 5 Basic lead silicate 6 Titanimn dioxide 50 Chromegreen 15 rative elements on the surface of the sheet in spacedrelationship so that they covered approximately 15% of the sufiace ofthe sheet. The matrix sheet carrying the decorative elements was thenpassed through a bank of infra red heating lamps wh ch raised thetemperature of the sheet to 350 F. The heated matrix sheet was then fedat a rate of twenty-five feet per minute between two steel rolls havingdiameters of 24 inches. The top roll contactlag the decorative elementad the surfaceof the matrix sheet had a polished chrome surface and washeated to.

shown in Fig. 2. 0n the oflmr hand, sheets of heavia 75 275 F.'lherollcomacting the back of the matrixsheet was maintained at atemperature about 195 F. The rolls were adjusted so that the sheet, uponpassing from the rolls, had a thickness of about 0.025 inch. The sheetthus produced was allowed to travel with its surface in adherent contactwith the surface of the chrome roll for approximately one-halfrevolution at which point it was stripped from the roll. The sheet wasthen passed over cooling rolls to reduce its temperature to about 100 F.and laminated to a bitumen impregnated felt having an adhesive coating.The product was then wound onto a collecting roll. The decorative sheetproduced had a smooth, glossy surface with the design elements, havingtheir original rectangular shape, firmly embedded in the surface of thesh .t to a depth of about two-thirds the thiclmcss of the sheet.

While certain equipment has been illustrated in the drawings anddescribed hereinauove which may be employed in the practice of thisinvention, it is to be understood that this ha been done in order toillustrate the practice of this invention so that an understandingthereof may be facilitated and that other types of equipment may beemployed for providing a heated matrix sheet of polyvinyl compositionhaving numerous sheet-form pressedin pieces distributed thereof insubstantially spaced relation and for pressing the pieces into the heatplasticized matrix sheet in the manor: and for the purposes hereinabovedescribed.

What is claimed is:

l. A method of mfiing a decorative and wear-resistant fierible surfacecovering for doors, walls and the like, which comprises d sposing insubstantially spaced relation on the surface of a preformed sheet ofthermoplastic pol 'vinyl composition numerous preformed fiat pieces ofpolyvinyl composition of contrasting color, heating said sheet to atemp-mature at which said szfiace is readily deformable and pressingsaid pieces flatwise into said heated sheet while said surface isdeformable with a smooth surface maintained at a temperaturesubstantially below the temperature of. said heated sheet until theexposed surfaces of said pieces are flush with the surface of said sheetthereby fusing said pieces to said sheet at their interfaces therewithwithout substantially distorting the shape of said pieces.

2. A method of making a decorative and wear-resistant flexible smoothsurface covering for floors, walls and the like, which comprisfsdisposing in substantially spaced rela ion on the surface of a preformedmatrix sheet of polyvinyl composition numerous flat pieces of polyvinylcomposition whose coloration contrasts with that of said matrix sheetand which are substautiflly thinner than said matrix sheet and have anarea of less than about 2% square inches in scrim area, heating thesheet to a temperature at which said surface of said preformed matrixsheet is deformable and pressing said pieces flatwise into said heatedsheet while said surface is deformable with a. smooth su'face maintainedat a temperature substantially below the temperature of said heatedsheet until the exposed surfaces t creof are flush with the surface ofsaid matrix sheet thereby fusing said pieces to said sheet withoutsubstantially distorting the shape of said pieces to form a smooth anduniform sheet, said pieces during said pressing step being at least atthe exposed surfaces thereof at a substantially lower temperature and ofharder consistency than said mairix sheet.

3. Amethod of making a decorative and wear-resistant flexible smoothsurface covering for floor, walls and the like, which comprisesdisposing in :ubstantially spaced relation on the surface of apreformed. sheet of polyvinyl composition mmrerous flat pieces of sheetmaterial composed of similar polyvinyl cornposiiicn'- having colorationcontrasting with that of said sheet, heating said sheet and fiat piecesto a temperamre at which said surface of said preformed sheet isdefomrable between about 350 F and about 390 F, pressing said piecesinto said sheet while said surface is deformable with a smooth hard sun-4 face maintained at a temperature substantially below the temperatureof said heated sheet until the exposed surfaces thereof are flush withthe surface of said sheet thereby formiry a smooth, uniform sheet andcooling the resulting sheet. 7

4. A method of making a decorative and wear-resistant flexible smoothsurface covering which comprises disposing in substantially spacedrelation on the surface of a preformed sheet of polyvinyl compositionnumerous preformed fiat pieces of polyvinyl composition whose colorationcontrasts with that of said sheet, heating said sheet to a temperatureat which said surface of said preformed sheet is deformable, passingsaid sheet while said surface is deformable between a first rollpresenting a hard, rigid surface maintained at a temperaturesubstantiaily lower than that of said heated sheet and a second rollcomprised at least at and adjacent the surface thereof of yieldableresilient material, said first roll contacting c said pieces andpressing; them into said sheet while said sheet is supported by saidsecond roll until the exposed surfaces of said pieces are substantiallyflush with the surface of said sheet thereby forming a smooth anduniform sheet without distorting the shape of said pieces.

5. A method according to claim 4 wherein said sheet is heated to atemperature in the range from about 3 0 F. to about 390 F. immediatelyprior to passage between said rolls, said preformed flat pieces are lessthan about one square inch in area, and the surface temperature of saidfirst roll is not greater than about F.

6, A method of making a decorative and wear-resistant flexible smoothsurface covering for iloors, walls and the like which comprisesdisposing in substantially spaced rela ion on the surface of a preformedmatrix sheet of polyvinyl composition numerous preformed flat pieces ofpolyvinyl composition of contrasting color, heating said matrix sheet toa temperature at which said surface is deformable, pressing said matrixsheet with said pieces disposed thereon whilc said surface is deformablebetween a surface presented by yieldable resilient material in contactwith said matrix sheet and a surface presented by hard, rigid materialthat is maintained at a temperature lower than that of said matrixshe-ct until the surfaces of said pieces are flush with the surface ofsaid matrix sheet I with resultant formation of bulges from the surfaceof said matrix sheet opposite to that into which said pieces are pressedin the places where said pieces occur, and thereafter planing off saidbulges to provide a composite sheet of substantially uniform thicknessthroughout having a smooth upper surface.

7. A method according to claim 6 wherein said pieces are substantiallythinner than said matrix sheet and are less than about one square inchin area, said matrix sheet is heated to a temperature between about 350F. and 390 F. immediately prior to said pressing and said press ing ofsaid matrix sheet with said pieces is effected between. a rollcontacting said matrix sheet that presents a body of elastomer on thesurface thereof and a hard, rigid, smooth surface metal roll thatcontacts said pieces and that is maintained at a temperature not aboveabout 130 F., and said matrix sheet is cooled after said pressing stepand prior to said planing off of said bulges.

8. A method of making a flexible smooth surface covering for floors,walls and the like, which comprises disposing on the surface of a smoothcalendered polyvinyl composition sheet a. pluralit of fiat pieces ofpolyvinyl composition having a higher softening temperature than thesheet, heating the sheet and fiat pieces to a temperature at which saidsurface is deformable and pressing the pieces into said deformablesurface .vith a smooth hard surface maintained at a temperaturesubstantially below the temperature of said heated sheet until theexposed surfaces of the pieces are flush with the surface of the sheetthereby fusing the pieces to the sheet at their interfaces therewithwithout substantially distorting the shape of said pieces.

9. A method of making a flexible smooth surface covering for floors,wins and the like which comprises preheating a smooth calcndcred sheetof polyvinyl composition to a temperature between about 250 F. and about356 R, disposing c-r; tn: upper surface of the preheated sheet aplurality of flat pieces of polyvinyl composition having colors thatcontrast with the color of the sheet, heatingair: street with the piecesdisposed thereon to a temperature at which said upper snriace isdeformable 'octwccr abort 356 F. and about 399 F. and pressing thepicccs into the heated sheet while said surface is deforma'olby passingbetween a hard surface roll rna tained at a te- .pet" ture substantiallylower than that of fire sheet and a second roll until J16 exposedsurfaces of me pies are flesh wit: the surface of the sheet therebyfusing the pieces to the sheet at their interfaces therewith and forminga sheet having a smooth and uniform. surface, the rolls disposed so thatthe hard surface roll contac s the pieces during the pressing.

1 A method of making a flexible smooth surface covering for doors, wall;and the like which comprises forming a smooth sheet of polyvinylcomposition comprising about 26 to 50 percent polyvinyl resin, about to30 percent plastifier and about 20 to 76 percent pigments and fillers, dsposing on the upper surface of the sheet a plurality of fiat pieces ofsimilar polyvinyl composition in colors which contrast with the color ofthe sheet and being less than about two and a quarter square inches inarea and at least one third the thickness of the sheet, neatct to atemperature at which said upper surface is actor-stable, passing theheated sheet while said surface is deformable between two calenderrolls, one calender roll having: a hard surface maintained at atempcrature substantially lower than the temperature of the sheet whichcontacts the pieces, thereby pressing and {using the pieces so that theexposed surfaces thereof are substantially flush with the surface of thesheet and r'used to the sheet at their interfaces therewith andlaminating the sheet thus formed to a felt backing material.

ll. 1; method of 2; king a decorative and wear-rsistant flexible surfacecovering for doors, walls and the like which comprises di posing insubstantially spaced relation on the su ace of a preformed sheet ofthemeplastic poiyrlnyl chloride composition numerous preformed fiatpieces of polyvinyl chloride composition of contrasting col r,31eatingsaid sheet to a temperature at which said sin-face is Kadily deformableand pressing said pieces fiatwise into said heated sheet while saidsurface is deformable win asmooth scrim maintained ata temperaturesubstantially below. the temperature of said heated sheet until theexposed surfaces of said pieces are flush with the surface of said sheetthereby fusing said pieces to said rheet at their interfaces therewithwithout substmtially distorting the shape of said pieces.

12. A method of making a decorative and wear-zesistant flexible smoothsunace covering for floors, walls and the like, which comprisesdisposing in substantially spaced relation on the surface of a preformedsheet of polyvinyl chloride composition numerous fiat pieces of sheetmaterial composed of similar polyvinyl chloride composition havingcoloration contrasting with that of said sheeL heat n said sheet andfiat pieces to a torn peratnrc at which sari-:2 surface of saidpreformed sheet is deformable between about 350 F. and about 390' F.,pressing said pieces into said sheet while said surface is deformablewith a smooth hard surface maintained at a temperature substantiallybelow the temperature of said heated sheet until the exposed surfacesthereof are flush the surface of said sheet thereby forming a smooth, unform sheet and cooling t'ie resulting sheet.

13. A method of making a flexible smooth surface covering for floors,walls and the like which comprises disposing on the surface of a smoothsheet of polyvinyl composition a plurality of fiat pieces substantiallythinner than the sheet of similar polyvinyl composi'ion having colorsthat contrast with the color of the sheet and having a thicknessexceeding one-third the thickness of the sheet, heating the sheet to atemperature at which said surface is deformable, the temperature beingless than about 390 F. passing the heated sheet while said surface isdeformable between a hard surface roll maintained at a temperaturesubstantially lower than that of the sheet and a second roll therebypressing the pieces until the exposed snziaccs thereof are substantiallyflush with the surface of s sheet without substantially distoring theshape of s: to nieces the rolls being disposed such a way that the hardsurface roll contacts the pieces before ihe sheet is passed between thetwo rolls.

14. The method of claim i3 wherein the thickness of the pieces isbetween one-third and one-half the thickness of the sheet, the sheet isheated to a temperature between about 350 F. and about 390 F. and thehard surface Fredrilzsen Dec. 12, 1933 l-leppes Aug. 31, 1937 Mondaleno. r em, on...

1. A METHOD OF MAKING A DECORATIVE AND WEAR-RESISTANT FLEXIBLE SURFACECOVERING FOR FLOORS, WALLS AND THE LIKE, WHICH COMPRISES DISPOSING INSUBSTANTIALLY SPACED RELATION ON THE SURFACE OF A PREFORMED SHEET OFTHERMOPLASTIC POLYVINYL COMPOSITION NUMEROUS PREFORMED FLAT PIECES OFPOLYVINYL COMPOSITION OF CONTRASTING COLOR, HEATING SAID SHEET TO ATEMPERATURE AT WHICH SAID SURFACE IS READILY DEFORMABLE AND PRESSINGSAID PIECES FLATWISE INTO SAID HEATED SHEET WHILE SAID SURFACE ISDEFORMABLE WITH A SMOOTH SURFACE MAINTAINED AT A TEMPERATURESUBSTANTIALLY BELOW THE TEMPERATURE OF SAID HEATED SHEET UNTIL THEEXPOSED SURFACES OF SAID PIECES ARE FLUSH WITH THE SURFACE OF SAID SHEETTHEREBY FUSIJG SAID PIECES TO SAID SHEET AT THEIR INTERFACES THEREWITHWITHOUT SUBSTANTIALLY DISTORTING THE SHAPE OF SAID PIECES.